In previously known methods and pipe connections intended for pipe connection between the feeding and/or return flow pipes and radiators, the work involved has been time consuming and complicated, mainly since it is extremely difficult to match the pipe connections of the radiators with the feeding and return flow pipes for temperate and circulating water is a closed circuit hot water system. The feeding and return flow pipes are, as a rule, first attached to the wall surfaces in a building, whereafter the radiators are fixed and connected to said pipes, which are arranged with pipe connection means, fitted prior to the attachment of the pipes. The position of the radiators are thus predetermined in relation to said pipe connection means and it is most difficult to alter these predetermined positions, which often can be necessary. When using previously known methods and pipe connection means, it is necessary to arrange separate valves for fluid flow adjustment and flow restricting purposes in various positions in the pipe system, to enable adjustment of the fluid flow rate. These valves are very expensive to purchase and install.